High energy magnesium-containing polymeric compositions



United States Patent 31,247,268 Patented Apr. 19, 1966 3,247,268 HIGH ENERGY MAGNESEUM-CGNTG PQLYMERHC CDMPOSITIONS Gaetano F. DAlelio, South Bend, Ind, assignor, by direct and me'sn'e assignments, to Dal Mon Research 60., Cleveland, ()hio, a corporation of Delaware No Drawing. Filed on. 18, 1961, Ser. No. 145,961 20 Claims. (Cl. 260-665) This invention relates to polymers containing magnesium. This application is a continuation-in-part of applicants copending applications Serial Nos. 746,643, filed July 7, 1958; 761,469, filed September 17, 1958; and 762,- 228, filed September 22, 1958, each of which is now abandoned.

Because of the high energy content of such compounds, magnesium compounds having magnesium to carbon bonds, such as magnesium alkyls, should be useful as fuel compositions. However, because of their tendency to ignite spontaneously upon exposure to air, and th highly reactive nature of these compounds, .the use of magnesium alkyls involves considerable danger and necessitates various precautionary steps. Moreover, since they are liquids, their use as propellant fuels for rockets, missiles, and relat-ed devices, has the drawback common to liquid fuels in that complicated containers and pumping devices are requi-red, and the sloshing elfect of the liquids in their containers causes shifting of weight which adversely affects directional control.

In accordance with the present invention, polymeric magnesium compounds have been discovered which have more easily controlled flammability and reactivity while still retaining high energy content. Such polymeric materials can be made in a solid state and thereby have the inherent advantages of solid fuels used for propelling purposes.

The polymeric compositions of this invention are prepared from magnesium hydrides, and hydrocarbon-substituted magnesium hydrides, by reaction with hydrocarbon compounds (including those having substituents thereon which are nonreactive to the magnesium hydrides and substituted hydrides), having a plurality of ethylenically unsaturated groups therein, or at least one acetylenic group therein, including polymers containing such groups.

Such compositions can be made in liquid or solid form, and can be converted to infusible forms. These polymeric compositions are useful as high energy fuels, either as a supplement or as a main component, and are particularly useful in the solid form for such purposes. Particularly useful infusible solid fuels can also be made by incorporating a solid or liquid oxidizing agent into the polymeric compositions of this invention while they are in a liquid or thermoplastic state, and then converting the polymer to a crosslinked, infusible condition.

Typical examples of the hydn'des and hydrocarbon substituted hydrides of magnesium which can be used in the practice of this invention include, but are not limited to, the following: magnesium hydride, magnesium alkyl hydrides, such as methyl magnesium hydride, ethyl magnesium hydride, propyl magnesium hydride, butyl magnesium hydride, octyl magnesium hydride, nonyl magnesium hydride, styryl magnesium hydride, cyclohexyl magnesium hydride, phenyl magnesium hydride, dimethyl magnesium, diethyl magnesium, methyl ethyl magnesium, dipropyl magnesium, dibutyl magnesium, ethyl butyl magnesium, diamyl magnesium, dioctyl magnesium, distyryl magnesium, methyl phenyl magnesium, dicyclohexyl magnesium, ethyl cyclohexyl magnesium, dicyclopentyl magnesium, etc. These magnesium compounds, sometimes generally referred to hereinafter as magnesium hydride compounds, can be used as such or in various complex forms, such as complexes with ethers, tertiary amines, thioethers, etc.

It has been found, in accordance with this invention, that polyalkenyl or acetylenic compounds, such as butadiene, acetylene, etc, and the magnesium hydride compounds can be made to react in such a manner as to produce polymers having magnesium in the polymer chain, and in relatively high proportions. The lower limit on the proportions of polyalkenyl or acetylenic compound will vary according to its functionality. For example, the polymeric products can contain as little as 0.67 mole of dialkenyl or acetylenic compound per atom of magnesium, and as little as 0.33 mole of trialkenyl compound per atom of magnesium. While even more olefin can be used, depending on how low a percentage of magnesium is desired in the polymer, it is generally desirable to have no more than about 1.5 moles of polyalkenyl or acetylenic compound per atom of magnesium in the polymer. The range is advantageously between about 1 and 1.5 moles of polyalkenyl or acetylenic compound per atom of magnesium. On the basis of metal equivalents, the general range is translated to mean from less than about 0.5 mole to about 0.8 mole of unsaturated compound per equivalent of magnesium. However, when other metals are substituted in part for the magnesium, as indicated hereinafter, these proportions are modified accordingly.

The polymeric products of this invention range from viscous oils to solid thermoplastic or thermoset resins. Depending upon the particular starting materials, modifiers, and polymerization conditions, the polymers range in molecular weight from about 300 to 100,000 and higher.

The polymeric products of this invention are represented by the formula wherein R is hydrogen or a hydrocarbon radical, n is an integer having a value of at least 2, preferably at least 4, and Y is a polyvalent radical derived from the acetylenic and ethylenic compounds and having as many valencies as there are magnesium atoms attached thereto. When derived from a dialkenyl compound or from a monoacetylenic compound having no ethylenic groups therein, Y is a divalent radical. When derived from a monoacetylenic compound, which also has one ethylenic group therein, or from compounds having a plurality of acetylenic groups therein, or from compounds having more than two ethylenic groups therein, Y can have more than two valencies. When derived from a polymer having a considerable number of ethylenic or acetylenic groups therein, Y also has more than two valencies. The R hydrocarbon radical preferably has no more than 24 carbon atoms. A hydrocarbon nucleus of R can have attached thereto substituents which are non-reactive toward the metal compound used in the preparation of the polymer. Also additional unreacted ethylenic and acetylenic groups may also be present.

Polymers of this invention have a plurality of repeating units therein, which can be represented by the formula 3 -Mg-Y in which Y is a polyvalent hydrocarbon r-adical. Some of these polyvalent hydrocarbon lIa'dlOHlS can be derived from a hydrocarbon compound having a plurality of ethylenic groups therein and having the formula CR =CRZCR=CR wherein R represents hydrogen or a hydrocarbon group, and Z represents a single bond between the two carbon atoms adjacent to Z, or a polyvalent hydrocarbon group. The hydrocarbon nucleus of R and of Z can have attached thereto substituents which are nonreactive toward the magnesium hydride compound used in the preparation of the polymer. However, acetylenic or additional ethylenic groups can also be attached to R and Z.

Certain polyvalent hydrocarbon radicals as represented by Y can also be derived from hydrocarbons having acetylenic or allenic unsaturation therein.

While it is believed that each magnesium atom becomes attached to one of the carbon atoms of an ethylenic or acetylenic group, it is also possible that the magnesium migrates during or after the reaction between the magnesium hydride compound and the polyalkenyl or acetylenic compound, and becomes attached to another carbon atom of the resultant compound that gives a more stable derivative. Thus, the magnesium may actually be attached to one of the R groups, or to Z. For that reason, Y groups derived form polyalkenyl compounds can be represented as a polyvalent radical having the formula C R H-Z-C R H in which the specific carbon atoms to which the magnesium is attached are not specified.

In polymers derived from polyalkenyl hydrocarbon compounds, Y can be replaced by the above formula in which the actual points of attachment of the magnesium are not pinpointed, as follows:

When the magnesium becomes attached and does not migrate from the ethylenic group, the polymeric product from polyalkenyl compounds can be represented by the following formula:

l. R- H (n ddn z du-dml H MgR or generally can be simplified, particularly where the ethylenic groups are vinyl or vinylidene groups, to:

I I (C 11;)20 @1120 (C 11 Accordingly, the polymeric products of this invention derived from acetylenic compounds can be represented by the formula:

When the magnesium becomes attached and does not migrate from the acetylenic group, the polymeric product is represented by the following formula:

In the above formula the various symbols are as previously defined and additional acetylenic or ethylenic groups can also be attached to one or more Rs.

Likewise, the polymeric products derived from allenic compounds are believed to be represented by the corresponding formulas:

and

3 2 4)n respectively.

When the magnesium hydride compound has no more than one hydrocarbon group attached to each magnesium: atom, such as magnesium hydride, ethyl magnesium hydride, methyl magnesium hydride, propyl magnesium hydride, styryl magnesium hydride, etc., and an acetylenic or allenic compound is used, it is believed that polymerization proceeds linearly, at least initially, as follows:

When a magnesium compound is used which has two hydrocarbon groups on each magnesium atom, the hydrocarbon groups can be displaced by the acetylenic or allenic compounds and the R groups liberated as the corresponding olefin. For example, when the two Rs on each magnesium atom are hydrocarbon groups, the polymer is believed to proceed linearly, at least initially, as follows:

In accordance with the preceding, the polymers of this invention have a plurality of repeating units therein of the formula Mg-Y. In these repeating units, Y is a polyvalent hydrocarbon radical as defined above. Specific Y radicals which fit this description appear in the following repeating formulas which represent the products and various examples described hereinafter. For example, in Example I, the polymers have a repeating unit structure of MgC H C H C H In Example IV, the product has a repeating unit structure of -Mg-C H The product of Example V has a repeating unit structure of --MgC H (CI-I In Example VI, the polymer resulting from reaction of diallyl benzene has a repeating unit structure of Mg-C H C H C H and the polymer resulting from reaction of divinyl naphthalene has a repeating unit structure of -MgC H C I-I C H In Example VI, the polymer resulting from the reactionof divinyl diphenyl has a repeating unit structure of -MgC I-I C H C H C H In Example VII, the polymer resulting from the reaction of divinyl cyclohexane has a repeating unit structure; Of MgC H C H C H In Example IX, XI and XII, the resultant polymers, have repeating unit structures of -MgC H -MgCzH3 la s respectively.

Infusible polymers can be obtained in the practice of this invention by using a hydrocarbon compound having three or more ethylenic gr ups therein, or at least one acetylenic and one ethyleni-c group or a plurality of acetylenic groups therein, or by using, together with the magnesium hydride compound, a trivalent metal compound, such as the boron and aluminum hydrides and their hydrocarbon-substituted hydrides. When the aboveindi cated types of unsaturated compounds are used, the crosslinking is eifected through another Y group, which can also be represented by the various formulas indicated above for Y. When a trivalent metal compound is used, such as a boron or aluminum hydride, together with the magnesium hydride compound, the crosslinkage can also be represented as a Y group which will be connected between polymer molecules through the trivalent metal atoms.

For example, when crosslinking is eifected through a copolymerized trivalent metal atom such as aluminum, it is believed that the crosslinked portions of the polymer can be represented as Y can also be represented as C R HZC R H, C2H2R2 01' C3H2R4.

In the polymerization described herein, when conditions permit, the hydrocarbon group which is replaced by the polyalkenyl or acetylenic compound, generally escapes from the system as an olefin. In cases of closed systems, the buildup of pressure, or the reluctance of a radical such as phenyl toward olefin formation, can result in the attachment or the hydrocarbon group to the carbon atom of the ethylenic or acetylenic group, other than the one to which the magnesium is attached.

Various modifications of polymeric materials can be made according to the practice of this invention by adjusting the proportions of reactants and the conditions under which the materials are made to react. For example, the amount ot crosslinking is controlled by the amount of compound having three or more ethylenic groups, etc., therein that is added, or the amount or" trivalent metal compound that is :added (for that purpose. T he selectivity, type of reaction, and product, can be controlled somewhat by selecting appropriate magnesiurn compounds, concentration thereof, polyalkenyl or acetylenic compound, and also by the use of certain amounts of monoalkenyl compounds. For example, since the hydrogen in these magnesium compounds is generally more easily replaced than alkyl compounds, it is possible thereby to control somewhat the type and extent of reaction.

When it is desired to control the molecular weight of a linear polymer, or to put terminal carbon groups on a polymer chain, this can be accomplished by using a mono-olefin, such as ethylene, together with the polyalkenyl (or acetylenic) compound. The latter can also be effected by using a monoor di-substituted magnesium, alone or together with unsubstituted magnesium hydride.

Some control over the type and extent of reaction can be efiected by using magnesium hydride compounds having hydrocarbon groups of different sizes. It is sometimes desirable, also, that the hydrocarbon groups to be replaced by the polyalkenyl or aicetylenic compound be of a smaller size than the polyalkenyl or acetylenic compound. This is particularly desirable Where there is displaced hydrocarbon group escaping as a byproduct olefin. In some cases, a polyalkenyl or acetylenic compound of higher boiling point than the resultant olefin permits escape or the olefin upon refluxing of the polyalkenyl or acetylenic compound, or upon maintaining the reaction temperature below that at which the polyalkenyl or acetylenic compound vaporizes to an und sirable extent. In some cases, particularly where the difference in volatility is not great, the olefin can be permitted to escape in a stream of the polyalkenyl or acetylenic compound passing through the system, or in a stream of inert gas with additional polyalkenyl or acetylenic compound being fed to the system. In cases where the polyalkenyl or acetylenic compound has a higher vapor pressure than any olefin that might be given off as byproduct, a closed system can advantageously be used to favor the desired displacement.

The temperature conditions for the promotion of polymer formation, in accordance with the practice of this invention, vary in accordance with the reactivity of the reagents being used. When a magnesium hydride is being reacted with a polyalkenyl or acetyleni'c compound, a temperature in the range of 7080 C. is generally suitable. When magnesium hydride compounds containing both hydrogen and hydrocarbon groups are used, the reaction can be controlled mainly to displace the hydrogen by keeping the temperature below C. Whenhydrocarbon groups are to be displaced from a magnesium hydride compound, a temperature of about 100-l20 C. is preferred. Depending upon the decomposition temperatures of the particular reagent, and the polymeric product, it is generally advantageous not to exceed a temperature of about C. When a mixture of a magnesium hydride and a magnesium hydride compound containing hydrocarbon groups is being used, it is generally desirable to maintain the appropriate temperature until most of the hydrogen has been displaced and then to raise the temperature to that more suitable for displacement of the hydrocarbon group. In some cases the temperature control can be facilitated by the use of an inert solvent, such as heptane, octane, benzene, toluene, xylene, etc., whose boiling point is close to the desired temperature.

The time required for polymer formation varies in accordance with the reactivity of the ethylenic or acetylenic groups in the polyalkenyl or acetylenic compound, the type of group to be displaced in the magnesium hydride compound, the temperature being used, and various other factors which favor the reaction, such as the use of metal catalysts, such as nickel, cobalt, etc., the removal or the byproduct olefin, etc. With respect to the last condition, an increase in concentration of such byproduct olefin promotes an equilibrium which competes with the progress of the polymer formation. Therefore, unless the olefin is permitted to escape, or it is absorbed by addition, this tends to slow down the polymerization. The polymerization proceeds most rapidly with vinyl groups in the polyalkenyl or acetylenic compound. Vinylidene groups also react rapidly when the second group attached to the doubly substituted carbon is relatively small. With larger groups in that position, longer reaction times and increased temperatures, but still below decomposition temperature, are desirable. Terminal acetylenic groups are more reactive than internal acetylenic groups, and ethylenic groups having hydrocarbon groups attached to both the alpha and the beta carbon atoms are still less reactive than the vinylidene groups, and require longer reaction time even at the more favorable temperature conditions. The time will also vary in accordance with the degree of polymerization required. While the more active reagents can give polymers in even less time, many of the polymeric products of this invention can be produced at moderate temperatures in a matter of 12 to 48 hours. In some cases, such as, with the non-reactive type of ethylenic groups, or when low temperatures, for example as low as 50 C., are used, much longer reaction periods are desirable. In such cases, the reaction is continued until a solid product is obtained.

Pol-yalkenyl compounds that can be used in the practice of this invention include those having the formula R C:CRZCR=CR wherein R and Z are as de fined above. Typical polyalkenyl compounds that can be used in the practice of this invention, include, but are not limited to, the following: 1,3-butadiene, isoprene, 2,3-dimethyl butadiene, pentadiene-1,3, hexadiene-2,4, octadiene-2,4, hexatriene-l,3,5, 2 phenyl4butadiene, 1,4-pentadiene, hexadiene-l,5, 2,4-dimethyl-pentadicue-1,4, vinyl cycloheXene, 1-phenylpentadiene-l,3, divinyl cyclohexane, diallyl, 1,6-heptadiene, 1,8-nonadiene, 2,8-decadiene, 2,9-dimethyl-2,8-decadiene, divinyl cyclopentane, divinyl methyl cyclohexane, diallyl cyclohexane, diallyl cyclopentane, dibutenyl cyclohexane, dipentenyl cyclohexane, allyl cyclohexene, diallyl cyclohexen'e, divinyl @cyclohexane, l,7-diphenylheptadiene-1,6, 2,7-diphenyl-octadiene-1,7, etc.

Polyalkenyl aryl compounds which can be used in the practice of this invention include: divinyl benzene, trivinyl benzene, divinyl naphthalene, trivinyl naphthalene, divinyl diphenyl, trivinyl diphenyl, divinyl toluene, trivinyl toluene, divinyl Xylene, divinyl ethyl benzene, divinyl ch lorobenzene, divinyl methylnaphthalene, divinyl ethylnaphthalene, divinyl methyldiphenyl, divinyl ethyldiphenyl, vinyl isopropenyl benzene, vinyl isopropenyl naphthalene, vinyl isopropenyl diphenyl, vinyl isopropenyl toluene, vinyl isobutenyl benzene, vinyl isobutenyl naphthalene, vinyl isobutenyl diphenyl, vinyl allyl benzene, vinyl 'allyl naphthalene, vinyl allyl diphenyl, vinyl allyl toluene, vinyl allyl methylnaphthalene, diallyl benzene, triallyl benzene, diallyl naphthalene, triallyl naphthalene, diallyl diphenyl, triallyl diphenyl, diallyl toluene, diallyl Xylene, diisopropenyl benzene, diisopropenyl naphthalene, diisopropenyl diphenyl, diisopropenyl toluene, diisopropenyl methyl naphthalene, dimethallyl benzene, dimethallyl naphthalene, dimethallyl diphenyl, bis-(alpha-ethyl-ethenyl)- benzene, bis-(alpha-ethyl-ethenyl) -naphthalene, bis- (alpha-ethyl-ethenyl) diphenyl, bis (alpha vinylethyl) benzene, bis (alpha vinyl ethyl) naphthalene, bis(alpha-vinyl-ethyl)-diphenyl, vinyl (alpha-vinylethyD-benzene, vinyl alpha-vinyl-ethyl)naphthalene, vinyl (alpha-vinyl-ethyl)-diphenyl, etc.

Other polyalkenyl aryl compounds that can be used include: dipropenyl benzene, p-propenyl styrene, parapropenyl isopropenyl-benzene, dicrotyl benzene, dicrotyl naphthalene, dicrotyl diphenyl, dicrotyl xylene, bis-(4- vinyl n butyl) benzene, bis (5 isopropenyl nhexyl)-benzene, bis (5 methyl nonene 6 yl) diphenyl, ibis-(n-de-cen-S-yl)-toluene, di-cyclopentenylnaphthalene, di-cyclohexenyl-benzene, etc.

Typical acetylenic and allenic compounds that can be used in the practice of this invention include, but are not limited to the following: acetylene, methyl acetylene, ethyl acetylene, propyl acetylene, amyl acetylene, vinyl acetylene, diacetylene (butadiene), dipropargyl (hexadiene-1,5), hexadiene-2,4, allene, butadiene-1,2, 4- methyl-pentadiene-l,2, tetramethyl allene, phenyl a-cet ylene, phenylene diacetylene, para-vinyl phenyl acetylene, napht-hyl acetylene, cyclohexyl acetylene, cyclopentyl acetylene, naphthylene diacetylene, cyclohexylene diacetylene, dipropargyl benzene, dipropargyl naphthalene, dipropargyl cyclohexane, p-propargyl styrene, etc.

Compositions of this invention are also prepared from polymeric hydrocarbon materials containing a plurality of unsaturated groups therein, such as et-hylenic and acetylenic groups, by reaction with the metal compounds. The polymeric materials used in the preparation Otf these compositions have a molecular weight of at least about 500, advantageously above 1,000, and have an average of at least four unsaturated groups per polymer molecule, advantageously more than ten such groups per polymer molecule.

The polymeric starting materials include polymers of polyunsaturated hydrocarbon monomers in which substantially only one of the unsaturated groups has been reacted in forming the polymer, and a substantial amount Y! I MgX wherein X represents R or another Y group.

The reaction can be represented at least initially as follows:

YI Y" n M HR I n g liltgRlt For example, when a 1,2-butadiene polymer is reacted with MgR or MgHR to replace only one R group or only the hydrogen in the hydride, the reaction can be represented initially at least as:

When the R group is also replaced the resultant repeating unit structure can be represented by Thus when the 1,2-butadiene polymer shown above is further reacted to displace the second R group of the MgR the polymer will have a plurality of repeating units of the formula In such polymeric products the portion of the polymers consisting of the hydrocarbon portion having a plurality of the Y repeating units can be represented as Y, with MgR or MgY groups attached thereto. Thus, these polymeric products also fit the generic formula R[MgY-] MgR as described above.

Typical examples of polyunsaturated hydrocarbon monomers that can be used in the preparation of these polymeric starting materials are the polyunsaturated compounds listed above for use as such in the practice of this invention.

Polymers having pendant groups, such as vinyl or vinylidene groups or terminal acetylenic groups therein, such as in 1,2-polybutadiene types of polymers, are preferred in the practice of this invention, since they react more easily with the metal compounds, but is also possible to use polymers having ethylenic groups other than vinyl and vinylidene groups, and acetylenic groups other than terminal ones. In such cases, the reaction with the metal compounds can be completed satisfactorily 'by the application of higher temperatures, or longer reaction periods than are generally required with the vinyl, vinylidene, or terminal acetylenic groups. Methods of polymer preparation which favor the production of pendant types of unsaturated groups and methods of determining relative percentages of such groups are well known in the art. Typical unsaturated polymeric materials include uncured polymers and copolymers of butadiene, isoprene, divinyl benzene, 2,3-dirnethyl butadiene, uncured natural rubber, ethylene-acetylene copolymers, etc., as listed above for the formula R C=CRZCR:CR

Polymers having pendant vinyl, vinylidene, or terminal acetylenic groups, particularly useful in the practice of etc.

Typical polymeric starting. materials having ethyl-enic or acetylenic groups not of the terminal type include those having repeating units of the following types:

etc.

It is generally desirable to use proportions of the reactants in accordance with the properties desired in the polymer products. For example, if low molecular weight products are desired, molar proportions of the acetylenic or ethylenie compound in. excess of the theoretical proportions favor this. Where high proportions of the metal are desired, this is favored by use of excess. metal compound, and also by theme of compounds having a greater number of unsaturated groups therein. High proportions of metal in the product are also favored by the use of low molecular weight acetylenic and ethylenic compounds.

The addition reactions of thisinvention are promoted by organic ethers, such as for example, diethyl ether, diisopropyl ether, tetrahydrofurane, diglyme, vinyl ethyl ether, vinyl butyl ether, vinyl propyl ether, vinyl amyl ether, vinyl cyclohexyl ether, vinyl phenyl ether, vinyl tolyl ether, isopropenyl ethyl ether, isopropenyl isopropyl ether, isopropenyl' butyl ether, isopropenyl phenyl ether, isopropenyl amyl ether, isobutenyl ethyl ether, allyl methyl ether, allyl'et'hylether; allylpropyl ether, butenyl ethyl ether, butenyl. propyl' ether, pentenyl amyl ether, vinyl cyclohexyl ether, vinyl cyclopentyl ether, para-vinyl anisole, allyl benzyl ether, vinyl benzyl ether, vinyl phenethyl ether, isopropenyl phenethyl ether, etc., as well as corresponding dialkenyl ethers, such as divinyl ether, diallyl ether, etc., Such unsaturated ethers as indicated above can be added directly to the reaction mixture to serve as modifiers as well as catalysts. They can also be reacted with the metal compounds and'then added.

Typical mono-alkenyl modifiers that can be used in the practice of this invention include, but are not limited to, the following: ethylene, propylene, butene-l, butene-Z, hexene-l, hexene-2, p-butyl-ethylene, 2,4,4-trimethyl-l-pentene, 2,4,4-trimethyl-pentener2, cyclopentene, cyclohexene, styrene, l,l-diphenylethylene, vinyl cyclohexane, alpha-methyl-styrene, vinyl naphthalene, betamethyl styrene, allyl benzene, allyl cyolohexane, decene-l, decene-Z, decene-3, decene-4, decene-S, dodecene-l, dodecene-Z, tetradecene-l, hexadecene-l, cycloheptene, etc.

Various methods of practicing the invention are illustrated by the following examples. These examples are i9 intended merely to illustrate the invention and not in any sense to limit the manner in which the invention can be practiced. The parts and percentages recited therein, and also in the specification, unless specifically provided otherwise, refer to parts by weight and percentages by weight. Unless indicated otherwise, the terms polymer and polymeric are intended to include copolymers and copolymeric. Molecular weights given herein are Staudinger molecular weights.

EXAMPLE I A mixture of 82 parts of diethyl magnesium dissolved in parts of heptane is added to parts of divinyl benzene and is heated in an atmosphere of nitrogen to boil off the heptane. The temperature is raised and maintained at 100 C. Ethylene is gradually evolved from the reaction mixture. After heating for 72 hours, the reaction mixture is cooled and a solid product is obtained. This is ground with an equal weight of ammonium perchlorate. The resultant mixture burns vigorously when ignited and when testedfor propellant thrust shows excellent thrust properties.

EXAMPLE II The procedure of Example I is repeated except that in place of the divinyl benzene, a mixture of 104 parts of divinyl benzene and 30 parts of trivinyl benzene is used. In this case, an infusible product is obtained, which, after grinding with an equal weight of ammonium perchlorate, shows vigorous burning properties when ignited and excellent thrust properties.

EXAMPLE III The procedure of Example I is repeated, using in place of the diethyl magnesium a mixture of 55 parts diethyl magnesium and 38 parts of triethyl aluminum. An infusible product is obtained which, when ground with an equal weight of ammonium perchlorate, burns vigorously upon ignition and shows excellent thrust properties.

EXAMPLE IV The procedure of Example I is repeated using in place of the divinyl benzene, an equivalent weight of diallyl, omitting the heptane, and sealing the mixture under vacuurn in a glass tube. The resultant solid product shows similar burning and thrust properties as for the product of Example I.

EXAMPLE V The procedure of Example IV is repeated with similar results, using 45 parts of ethyl magnesium hydride and 68 parts of isoprene.

EXAMPLE VI The following procedure is followed a number of times, using in each case a different mixture as indicated in Table I below. The number appearing before a particular compound in this table and in subsequent tables, indicates the number of parts by weight of that compound used. In each case the mixture is maintained under an atmosphere of nitrogen and the temperature is raised gradually over a period of several hours and then maintained at 120-130 C. for a period of about 72 hours. In each case, the resultant solid product is processed as in Example I and upon testing exhibits excellent burning and thrust properties.

Table l 120 Diisopropenyl benzene 50 Triisopropenyl benzene 120 Diallyl benzene 50 Triallyl benzene Divinyl. naphthalene 50 1,2,3-triallyl0xy propane 285 Dieyclohexyl magnesium Dibutyl magnesium 265 Di-(3-phenyl-propyl) magnesium 1 1 EXAMPLE VII 130 Styryl magnesium hydride 65 Divinyl benzene 52 Trivinyl benzene 100 Trivinyl naphthalene 130 Divinyl cyclohexene 15 Trivinyl benzene 160 Diallyl cyclohexane 20 Triallyloxy propane 100 Octadiene-1,7

20 Octatriene-1,3,7

54 Ethyl magnesium hydride G8 Propyl magnesium hydride 102 Phenyl magnesium hydride 93 Cyclohexyl magnesium hydride EXAMPLE VIII Various mixtures indicated in Table III below are treated according to the following procedure. The mixture is heated in 150 parts of hexane, in each case, under a blanket of nitrogen under reflux for two hours. Then the hexane is slowly distilled off, and in accordance with the corresponding increase in reflux temperature the temperature is gradually increased to 7080 C. and maintained at that temperature for approximately five hours. Then the temperature is gradually increased to 120-130 C. for a period of 72 hours. A solid product is obtained in each case and upon processing as in Example I, each product exhibits excellent burning and thrust properties.

Table III 66 Cyclopentadiene 100 Vinyl oyclohexene 100 Trivinyl benzene 100 Octadiene-1,7

4O Octatriene-1,3,7 100 Diallyl 100 Divinyl benzene 25 Tristbets-ethoxy-ethyl) borene EXAMPLE IX A mixture of 14 parts of di-secondary-butyl magnesium, 0.5 part dioxane, and 50 parts of heptane is heated in an atmosphere of nitrogen at 50 C. Pure acetylene is bubbled into the solution at such a rate that the temperature does not rise above 55 C. When approximately 3 grams of acetylene has been absorbed, the acetylene supply is shut off and the temperature is maintained for an additional two hours. Then the temperature is raised gradually to distill otf the heptane, following which the temperature is taken to 120 C. for a period of 30 hours. The resultant solid product is ground with an equal weight of ammonium perchlorate. This mixture, when ignited and tested according to known tests for propellant thrust, shows excellent thrust properties.

EXAMPLE X The procedure of Example IX is repeated, using 8 parts of di-ethyl magnesium in place of di-butyl magnesium, and 4.5 parts of methyl acetylene in place of the acetylene. In three different tests, 4 parts of the resultant polymer are ground individually with 6 parts of ammonium perchlorate, lithium perchlorate, and potassium perchlorate, respectively. In each case, the mixture when ignited burns very rapidly with an intense White flame, and upon testing for thrust properties shows excellent thrust.

12 EXAMPLE XI The procedure of Example X is repeated, except that allene is used in place of the methyl acetylene. Similar results are obtained.

The same procedure used with an equivalent weight of propyl acetylene also gives similar results.

EXAMPLE XII The following procedure is repeated eight times, using in each case 14 parts of di-isobutyl magnesium, and with each experiment a progressively smaller amount of phenyl acetylene, as follows: 45, 33 22, 11, 9, 5.5, 3.3, and 2 parts, respectively. In each case, the mixture of di-butyl magnesium and phenyl acetylene is prepared at room temperature underan atmosphere of nitrogen, and then the temperature is gradually raised to C. and maintained there under the nitrogen atmosphere until the reaction mixture forms a solid cake and no more butene is released from the reaction. The product is ground with an equal weight of ammonium perchlorate. This mixture, when ignited and tested, according to known tests for propellant thrust, shows excellent thrust properties.

EXAMPLE XIII The procedure of Example IX is repeated, using 11 parts of dipropyl magnesium and 4.5 parts of vinyl acetylene. An insoluble product is produced which shows excellent burning and thrust properties.

EXAMPLE XIV To a solution of 28 parts of di-isobutyl magnesium in parts of heptane, covered by a blanket of nitrogen, is added 13 parts of phenylene diacetylene. The resultant mixture is heated under an atmosphere of nitrogen and the temperature is raised gradually to remove the heptane by distillation. Then the temperature is maintained in the range of l00120 C. for 48 hours. The resultant solid product is washed with heptane, and then ground with an equal weight of ammonium perchlorate. The resultant mixture, when ignited and tested, shows excellent burning and thrust properties.

The above procedure is repeated, using in one case cyclohexene diacetylene, and in another case naphthylene diacetylene in amounts equivalent to and in place of the phenylene diaoetylene used in the above procedure. In each case results are obtained similar to those indicated above.

EXAMPLE XV The procedure of Example XIV is repeated, using 38 parts of distyryl magnesium in place of the di-isobutyl magnesium. The resultant solid product, when ground with an equal weight of ammonium perchlorate, shows excellent ignition and thrust properties.

EXAMPLE XVI The following procedure is repeated a number of times, using in each case a different mixture selected from those indicated in the table below. The number appearing in the table before a particular compound indicates the number of parts by weight of that compound used. In each case the acetylenic or allenic compound, together with any solvent or modifier, is maintained under an atmosphere of nitrogen at a temperature of 50-55 C. In the case of vinyl acetylene, it is fed into the heptane solvent at such a rate that it is present in molecular excess to the amount of magnesium dihydride present. Any acetylenic or allenic compound lost from the system through volatilization is caught in a low temperature trap and returned to the system. A solution of 55 parts of magnesium hydride in 100 parts of ether is dropped into the reaction mixture while under a blanket of nitrogen, at such a rate that no more than 2. 5 rise in temperature occurs. When the temperature rises above 60 C., the magnesium hydride solution supply is cut oif or reduced until the temperature has subsided to the desired range.

"i3 During this addition period, the ether is allowed to vaporize from the reaction mass and is recovered by condensation at a point before the low temperature trap mentioned above. After all the solution has been added, the heating is continued for a period of two hours, after which the temperature is raised to the solvent reflux temperature for a period of ten hours, and where no solvent is used a temperature of approximately 80 C. ismaintained for that period. Then the solvent, where present is distilled oil. The resultant product in each case, upon testing as in Example I, shows excellent burning and thrust properties.

1'4 EXAMPLE XXI A mixture of parts of magnesium hydride, 0.5 part diethyl ether, and 100 parts of heptane is prepared and maintained under an atmosphere of nitrogen at 10 C. Pure acetylene is bubbled into the solution at such a rate that the temperature is raised only very slowly to no higher than -55 C. Volatile reactants escaping from the system are caught in a cold trap and returned to the reaction mixture. When approximately 3 grams of acetylene has been absorbed, the acetylene supply is shut ofi and the temperature is maintained at 50-55 C. for an additional 5 hours. Then, the temperature is raised grad- EXAMPLE XVII A mixture of 8 parts of diethyl magnesium and 10 parts of phenyl acetylene is heated under a nitrogen atmosphere at 70 C. for ten hours. The mixture is then cooled to room temperature and 10 parts of styrene, and 36 parts of finely ground ammonium perchlorate are added. The mixture is milled to uniformity and then press-cast in the; form of a rod and heated at 70 C. for 12 hours. A solid,- infusible product is obtained which shows excellent thrust properties.

EXAMPLE XVIII A mixture of 35 parts of distyryl magnesium, 20 parts of amyl acetylene, and 2 parts of para-allyloxy-phenyl acetylene is heated at C. in a sealed container for a period of 48 hours. The resultant solid product shows excellent burning and thrust properties.

EXAMPLE XIX A mixture of 20 parts of diethyl magnesium, and 7 parts of triethyl aluminum is heated under an atmosphere of methane for 15 hours at C. An insoluble, infusible product is obtained. This polymer is believed to have, at least in part, repeating units of the following structure:

By using equivalent amounts of triethyl borane and diethyl beryllium, respectively, in place of the triallyl aluminum, and in each case repeating the preceding procedure, two solid products are obtained which are believed to have, at least in part, repeating units of the following structu res ually to distill oil? the heptane, following which the temperature is taken to 80 C. for a period of 15 hours. The solid polymer product, when tested as in Example I, shows excellent burning and thrust properties.

The above procedure is repeated a number of times, With similar results, using in place of the magnesium hydride, an equivalent weight of:

Monoethyl magnesium hydride Monopropyl magnesium hydride Monobutyl magnesium hydride Monophenyl magnesium hydride Monocyclohexyl magnesium hydride EXAMPLE XXII A solution of 14 parts of di-secondary-butyl magnesium, 15 parts of solid, soluble polymer of divinyl benzene, and 02 part of diethyl ether in parts of toluene, is heated in an atmosphere of nitrogen at 50 C. for one hour. Then the temperature is raised to 70 C. for two hours, and thereafter refluxed for five hours. The toluene is then distilled off and the reaction mixture heated at l30 C. for 24 hours. The solid product is washed with heptane to extract traces of unconverted dibutyl magnesium. The washed product is more stable in air than the ordinary organo-magnesium compounds. The resultant product is ground with an equal weight of ammonium perchlorate. The resultant mixture, when ignited, burns very rapidly with an intense white flame, and when tested according to known tests for propellant thrust, shows excellent thrust properties.

parts of diethyl magnesium, in place of the dibutyl magnesium and 0.2 part of divinyl ether. In three different 02115 tests, 2 parts of the resultant polymer are ground individually with 8 parts of ammonium perchlorate, lithium and Mg (CH2)3 Be (cH2)3T respectively perchlorate, and potassium perchlorate respectively. In EXAMPLE XX each case, the mixture, when ignited, burns very rapidly with an intense white flame, and upon testing for thrust properties, shows excellent thrust.

approximately 60 percent of 1,2-polybutadiene structure. Similar results are obtained.

1 5 EXAMPLE XXV The procedure of Example XXII is repeated, except that in place of the divinyl benzene polymer, there is used, a solid, soluble butadiene polymer having approximately percent of 1,2-polybutadiene structure, and the final heating is conducted for 60 hours instead of 24. The product shows good burning and thrust properties.

EXAMPLE XXVI The following procedure is repeated eight times, using in each case 14 parts of di-isobutyl magnesium, and with each experiment a progressively smaller amount of a solid, soluble polymeric butadiene having approximately 60 percent 1,2-polybutadiene structure, as follows: 24, 18, 12, 6, 4.5, 3, 2 and 1.5 parts, respectively. In each case, the magnesium compound and the polymer are dis- :solved in 100 parts of benzene and heated under an at- :mosphere of nitrogen at 50 C. for a period of two hours, :and then refluxed for a period of ten hours. Then the benzene is distilled off and the reaction mixture heated under nitrogen atmosphere at 100-130 C. for 30 hours. 'The product in each case is treated as in Example XXII and shows excellent burning and thrust properties.

EXAMPLE XXVII The procedure of Example XXII is repeated, using 11 parts of dipropyl magnesium, 14 parts of solid, soluble polymer of para-allyl-styrene, and 0.3 part of di-(allylioxypropyl) magnesium. Similar results are obtained.

EXAMPLE XXVIII The procedure of Example XXII is repeated, using 12 parts of distyryl magnesium and 15 parts of a solid, soluble polymer of para-isopropenyl-styrene. The product shows excellent burning and thrust properties.

EXAMPLE XXIX The procedure of Example XXVII is repeated, using 15 parts of a solid, soluble polymer of para-vinyloxy-styrene,

100 parts of ether is dropped into the reaction mixture covered by a blanket of nitrogen, at such a rate that no more than a 5 percent rise in temperature occurs. When the temperature rises above 60 C., the magnesium hydride solution supply is cut olf or reduced until the temperature has subsided to the desired range. During this addition period, the ether is allowed to vaporize from the reaction mass. After all the solution has been added, the heating is continued for a period of two hours, after which the temperature is raised to the solvent reflux temperature for a period of ten hours. Then, the solvent is distilled oti and heating continued at 90 C. for an additional 15 hours. The resultant product in each case shows excellent burning and thrust properties.

Table I Polyunsaturated polymer ot Modifier or Catalyst 100 3-Vinyl oyclohexene 5 Diallyl ether 60 Ethyle)nc-aeetylene eopolymer (75-25 mole 1 Divinyl ether ratio 70 Isoorene 2 Allyl propyl ether 70 p-Vinyl phcnylaeetylene 10 Styrene 100 Diallyl ether 120 Divinyl benzene-Divlnyl ether eopolymer (80-20 mole ratio) 160 p-Vinyloxy-styrene 80 Uneured natural rubber 10 Diallyl ether EXAMPLE XXXII in e Butyl magnesium hydride 130 Styryl magnesium byr e 100 Phenyl magnesium hydride 75 Propyl magnesium hydride 110 Cyelohexyl magnesium hydride 70 Butadiene-styrene eopolymer 2 Tetrahydrofurau (7 5-25 weight ratio) Ethylene-acetylene eopolymer (75-25 mole ratio) 265 Divinyl benzene-ethyl styrene copolymer (50-50 weight ratio) 150 p-Allylexystyrene 50 Vinyl acetylene 5 Divinyl ether '2 Diethyl ether 10 Styrene 2 Diethyl ether in place of the para-isopropenyl-styrene, and omitting the di-(allyloxypropyl) magnesium. The product shows excellent burning and thrust properties.

EXAMPLE XXX The procedure of Example XXVII is repeated, using 16 parts of a solid, soluble polymer of para-allyloxy-styrene, in place of the vinyloxy-styrene. The product shows similar burning and thrust properties.

EXAMPLE XXXI The following procedure is repeated eight times, using .in each case a different mixture of soluble polymer and modifier or catalyst, selected from those indicated in the .table below. The number appearing in the table before .-a particular compound indicates the number of parts by weight of that compound used. In each case the polyunsaturated polymer dissolved in 100 parts of benzene,

together with any catalyst or modifier, is maintained under an atmosphere of nitrogen at a temperature of 50- 55 C. .A solution pf 2,6 parts of magnesium hydride and EXAMPLE XXXIII A solid, soluble polymer of divinyl benzene parts) is mixed under a nitrogen atmosphere with 60 parts dipropyl magnesium on a Banbury mixer. The resultant mixture is heated under nitrogen at 80 C. for 72 hours. The resultant product, when tested according to Example XXII shows excellent burning and thrust properties.

EXAMPLE XXXIV The procedure of Example XXXIII is repeated using 80 parts of dipropyl magnesium and 30 parts of styrene, in place of the 60 parts of dipropyl borane of Example XXXIII. Similar results are obtained.

EXAMPLE XXXV The procedure of Example XXXIII is repeated with similar results, using parts of dibutyl magnesium in place of the dipropyl magnesium.

EXAMPLE XXXVI The procedure of Example XXXIII is repeated using in place of the dipropyl magnesium, 230 parts of distyryl magnesium, and 100 parts of tributenyl aluminum. An insoluble, infusible product is obtained, which has excellent burning and thrust properties. This product has both magnesium and aluminum in the polymeric molecules.

By using equivalent amounts of dibutenyl boron and dibutenyl beryllium, respectively, in place of the tributenyl aluminum, and in each case repeating the preceding procedure, two solid products are obtained having similar burning and thrust properties. These polymeric products have boron and magnesium in the polymeric molecules of one, and beryllium and magnesium in the polymeric molecules of the other product.

EXAMPLE XXXVII Ten parts of the polymer of Example XXII is mixed uniformly with 40 parts of finely divided ammonium perchlorate in a solution of 9 parts of styrene, one part of a 50-50 commercial divinyl benzene-ethyl styrene mixture, and 0.1 part of benzoyl peroxide. The mixture is cast and maintained at 70 C. for 12 hours. An insoluble, infusible polymer product is obtained, which shows excellent burning and thrust properties.

EXAMPLE XXXVIII The procedure of Example XXXIII is repeated, using 140 parts of dibutenyl magnesium in place of the diprop-yl magnesium. The product shows excellent burning and thrust properties when tested as in Example I.

The polymerization described herein can be suspended at an early stage to give low-melting, solid polymers, or in some cases viscous oils, which can be stored as such and the polymerization reaction continued at a subsequent time. In fact, the reaction can be suspended when the product comprises substantially a monomeric product, such as, for example, that derived from a magnesium hydride compound and butadiene, namely:

and the polymerization completed later by the application of heat or the addition of magnesium hydride compounds or other reagents, catalysts, modifiers, etc.

Various modifiers can be added to the compositions of this invention after the polymerization is completed, and in cases where the modifiers are nonreactive with the magnesium hydride compounds, can be added prior to the initiation of the polymerization, or at some intermediate stage. Hydrocarbon materials, such as "arious hydrocarbon resins, e.g. polystyrene, polyethylene, polypropylene, polybutenes, paraffins, etc., can be added at any time. Certain other resins that might influence the reaction or be reduced or reacted upon by the magnesium hydride compound, such as those containing ester, amide, or other functional groups, can be added after the polymers are formed. However, if sufficient magnesium hydride compound is added to compensate for that used in such side reactions, such resins can often be added before or during the reaction. Typical resins include, polyethers, such as polymeric vinyl ethyl ether, polymeric vinyl butyl ether, etc., polyesters, such as polyvinyl acetate, polyvinyl propionate, polyvinyl butyrate, polymethyl methacryl-ate, polymethyl acrylate, etc., polyvinyl acetal, polyvinyl butyral, etc., polyacrylonitrile, polyamides, such as nylon and polymeric caprolactam, etc.

Various other polyunsaturated compounds, in addition to those indicated above, can also be added either before initiation of the polymerization, or at an intermediate stage, or at the completion of the polymerization reaction to modify the properties of the products. Such polyunsaturated compounds include: polyunsaturated ethers', and various alkenyl derivatives of boron, beryllium, and aluminum.

' Typical examples of such polyunsaturated compounds include, but are not restricted to, the following: divinyl ether, diallyl ether, vinyl allyl ether, propenyl vinyl ether, propenyl allyl ether, divinyl ether of resorcinol, divinyl ether of ethylene glycol, diisopropenyl ether, isopropenyl vinyl ether, isopropenyl allyl ether, isopropenyl butenyl ether, isopropenyl isoamylene ether, diallyl ether of resorcinol, diisobutenyl ether of hydroquinone, para-vinyloxy styrene, para allyloxy styrene, triallyloxy benzene, tripropenyloxy benzene, etc., triallyl borane, tetra-allyl diborane, tributenyl borane, tetrabutenyl diborane, dibutenyl beryllium, dibutenyl aluminum, triallyl aluminum, etc.

In addition to the polyalkenyl type of boron, beryllium, and aluminum compounds indicated above, it is desirable in some cases to add monoalkenyl derivatives of such metals and to continue replacement of the remaining hydrogen or saturated hydrocarbon groups on the metal by means of the polyalkenyl compounds, or by such compounds which have already partially reacted with magnesium hydride compounds. By these techniques, both magnesium and other metals can be incorporated in polymeric materials.

F or many purposes, such as fuel, it is desirable to have a high concentration of the magnesium polymeric units present in the compositions. In such cases, the modifiers are used in minor amounts. However, in certain cases, it may be desirable to use the magnesium compositions to modify or fortify the properties of other materials, in which case the magnesium derivatives are used in minor amounts.

As indicated above, the magnesium polymers of this invention are particularly useful as solid fuels. They can be used as the main fuel component or can be added to various types of other fuels to fortify or supplement such fuels. For example, they can be used as additives to gasoline and other motor fuels, to kerosene and other materials used for turbojet engines and jet engines, and can be added to liquid and solid propellant fuels used for rockets, missiles, etc. However, these polymeric compositions are particularly useful as the main fuel compound in solid propellant fuels for rockets and related devices. In such latter cases, it is advantageous to convert the fuel to an infusible form. If modifiers, or auxiliary agents, are to be added, this can be effected before conversion to infusibility. Depending on the particular manner in which the fuel is to be'used, it can be in solution, powder, rod, cylinder, or whatever other shape is convenient.

lVhile such products should be made and stored under inert atmospheres, it is surprising that considerable amounts of oxidizing agents can be incorporated into these polymeric compositions and can be stored in inert atmospheres 'without danger of premature ignition or explosion. The materials can simply be mixed in finely divided form, or where desired the oxidizing agent can be incorporated into a solid mass of the polymer. Moreover, after the desired amount of oxidizing agent has been incorporated into the polymeric composition, it can be converted to an infusible form by various means, including the addition of aluminum or boron hydrides and hydrocarbon-substituted hydrides, or by the addition of hydrocarbons and ether compounds having three or more ethylenic groups therein, together with the application of heat or catalysts to efiect crosslinking through the trivalent metals, or through the ethylenic groups, or by any other means of crosslinking.

Oxidizing agents which can be incorporated in the resin for the ultimate purpose of supporting combustion of the resin and which can be incorporated in accordance with safety conditions determined by their reactivity, include: the solid and liquid perchloryl aryl compounds of the formula A-rClO such as perchloryl benzene, perchloryl toluene, etc., various perchlorates, nitrates, oxides, persulfates, and peroorates of metals and ammonia, such as ammonium perchlorate, potassium perchlorate, sodium perchlorate, ammonium nitrate, potassium nitrate, sodium nitrate, potassium permanganate, potassium chlorate, manganese dioxide, potassium iodate, potassium dichromate, chloric acid, perchloric acid, ammonium persulfate, ammonium dichromate, ammonium iodate, aluminum nitrate, barium chlorate, barium perchlorate, barium per- 19 manganate, lithium perchlorate, lithium dichromate, lithium permanganate, etc.

Some of these oxidizing agents are not self-sustaining oxidizing agents, and can be used when free oxygen, or compositions such as perchloryl fluoride, highly concentrated hydrogen peroxide, etc., which generate oxygen in situ, are passed in surface contact with the fuel. The liquid oxidizing agents can be incorporated with precautions to assure uniform distribution through the polymer mass and to avoid ignition or explosive conditions during preparation and use of the fuel. It is desirable that the products from reaction of the oxidizing agent and the resin are gaseous in their normal state so that the energy developed in the system will not be robbed of energy to convert them to the gaseous state.

It is generally desirable that the fuel be molded in the shape in which it is ultimately to be used before .the composition is converted to an infusible state. In fact, the fuel can even be cast or molded as one entire unit which will comprise the entire fuel load for one rocket and can be substantially as long as the rocket if desired. Therefore, the size is limited only by the size of the rocket in which it is to be used.

It is possible to make the fuel in other shapes than indicated above and have the fuel machined to give the desired shape. For example, cylindrical shapes are generally desirable with an opening running through the cylinder along its linear axis. If desired, there can be a plurality of such openings running through the length of the mass so that more than one oxidizing stream can function simultaneously. However, various other shapes can be used, such as blocks having rectangular or square cross sections with one or more openings running along the linear axis of the block.

While the aforementioned shapes are preferred, it is also possible to use smaller units or shapes made by the practice of this invention, and then to assemble them in a space or container advantageously in such a manner that one or more open linear paths are left through the assembled mass so that the oxidizing gas and/or the combustion gases can be passed therethrough. For example, the fuel can be in the shape of discs with an opening in the center, or in half or quarter discs, or even with rectangular, square, or various other cross-sections so that upon assembly, one or more openings for the oxidizing gas are formed through the assembled mass. A cylindrical mass can be made of a number of concentric cylinders for which the outer diameter of one is slightly less than the diameter of the inside linear opening of another so that the assembled cylindrical rnass actually comprises a number of cylindrical sleeves which fit over one another. The axial opening of the one having the smallest diameter would be the linear axis opening of the assembled mass.

In addition to the foregoing, the resin-oxidizing agent composition can be made in various other shapes, depending on the manner in which it is ultimately to be used. As a further example, it can be shaped as a solid rod, in which case the burning surface will be the outer surface of the rod or cylinder. The outer surface of the rod can be ignited and if a supplementary oxidizing fluid is used, this can be directed against such outer surface of the rod. If desired, the rod can be advanced through an opening in accordance with the desired rate at which the surface is to be exposed to a supplementary oxidizing fluid. The composition can also be shaped in the form of granules, pellets, etc., where it is desired to modify the surface area that is to be exposed for combustion. Such granules can be used as such, or can be adhered to metal surfaces in accordance with the present known art in the use of solid propellant fuel in granular form.

When the oxidizing agent to be added is a solid, it is desirably in fine particle size so as to permit substantially uniform distribution throughout the mass. The oxidizing composition which is to be passed in surface contact with the fuel is of the type generally used presently, such as pure or highly concentrated oxygen. The upper limit in the amount of oxidizing agent to be used is determined by the concentration that can safely be used under the conditions ultimately existing in the fuel zone of the rocket, or by that excess over the stoichiometric amount required for complete combustion of the fuel, whichever limit is reached first. Obviously, the safety limit will vary according to the type of auxiliary oxidizing agent used. The type of fuel base material used together with its heat capacity and heat transmission properties, the temperature which will exist in the preparation and use of the fuel, etc.

Since the fuel composition of this invention can be used according to various methods, varying from the use of a substantial amount of supplemental oxidizing fluid to that in which the combustion is self-sustained-by the oxidizing compound contained in the fuel, the minimum amount of such oxidizing agent contained in the fuel will depend on the manner in which the fuel is to be used. When the combustion is to be maintained partly by an oxidizing agent in the fuel and partly by the oxidizing agent pumped through the opening, then obviously the supplemental effect of one agent toward the other will depend on the particular material being used as the oxidizing agent in the fuel and on the particular oxidizing fluid being fed through the opening.

Moreover, in each case the relative amounts cannot be determined on a weight basis but must be determined on the basis of the amount of oxygen available in the particular oxidizing agent used to support the combustion. This depends on the oxygen content of the oxidizing agent and the percent of the oxygen that is liberated for oxidizing purposes upon decomposition of the oxidizing agent. Furthermore, this depends somewhat on the efficiency with which it is desired to consume the fuel. For example, it might be desirable to have a considerable excess of oxidizing agent so as to consume the fuel more completely, even though it might mean an inefficient use of the oxidizing agent. Again, if it is permissible to use the fuel with a low eficiency for use of B.t.u. content, then it may be desirable to use a smaller amount of oxidizing agent.

The amount of oxidizing agent imbedded in the fuel itself can be further decreased when a supplemental oxidizing fluid is being pumped into contact with the fuel. Obviously, therefore, the proportion of oxidizing agent imbedded in the fuel base material can vary from 5 percent to approximately 95 percent depending on the various factors involved, such as the efliciency desired, the method and convenience of operation, and the materials being used. Generally, when an oxidizing agent is imbedded in the base material, it is advantageous to use from about 5 percent to 95 percent, preferably about 20 percent to about percent based on the combined weight of oxidizing agent, base material, and any crosslinking modifier that is used.

When an oxidizing agent is used in the fuel base material of the type and in the amount that will be selfsustaining in the combustion of the fuel base material, there will be no need to use an oxidizing fluid on the surface of the fuel, In such cases, the combustion of the fuel is initiated by igniting it by various means presently used for that purpose, such as a mixture of hydrazine, or unsymmetrical dimethyl hydrazine, and nitric acid, or by triethyl aluminum and oxygen, or by a torch, or by an electrical ignition system. When the oxidizing agent is not present in self-sustaining amount, liquid oxygen or an eflicient oxidizing compound such as perchloryl fluoride (F010 can be pumped into contact with the surface of the fuel to supply the oxygen for combustion. In some cases highly concentrated hydrogen peroxide, such as 98 percent hydrogen peroxide can be used to supply oxygen for combustion.

When a self-sustaining oxidizing agent is distributed throughout the fuel, the desirable amount can be determined by calculating the stoichiometric equivalent required for combustion of the fuel, and adjusting the calculation by subtracting, where less than 100 percent efiiciency is satisfactory, or adding, where desired, an excess to compensate for the lack of 100 percent efliciency in the actual combustion. Since the conditions of operation do not permit the time and type of mixing which give 100 percent eificiency, where other factors permit, it is sometimes desirable to have an excess of oxidizing agent which will give 50 percent, or even as high as 100 percent more than the stoichiometric amount of oxygen. When it is permissible or desirable to sacrifice some of the efficiency of the B.t.u. content of the fuel, the stoichiometric amount or even less than that amount of the oxidizing agent can be used, depending on the fuel efilciency desired.

The oxidizing agent and/ or modifier can be introduced or suspended in the solid fuel in any convenient or appropriate manner. The mixture can be effected mechanically as on mixing mills, on a Banbury mixer, any single or double worm extruder, or by rotation of the mold when the material is being cast from a liquid state. When a solid is to be added, the thermoplastic material can desirably be softened by the addition of a softening agent, or, as indicated above, by the modifier itself. Such compounded mixtures can then be extruded, or otherwise shaped into the desired form and then polymerized to infusibility. In some cases, depending on the particle size of the sold oxidizing agent and the amount of void space between particles, the polymer in liquid state, or the monomer from which it is to be prepared, together with a polymerization catalyst of the peroxy or azo type, can be poured into a container holding the solid oxidizing agent and thereby fill the void spaces. Then upon standing at room temperature, or at slightly raised temperatures, the polymer or monomer will be converted to an infusible state with the oxidizing agent embedded therein.

However, whichever method of mixing is used, it is desirable to avoid the generation of heat that will raise the temperature to the ignition point of the oxidizing agent. Therefore, in some cases, it is desirable to precool the materials to be mixed or to provide means to withdraw the heat as it is generated.

While certain features of this invention have been described in detail with respect to various embodiments thereof, it will, of course, be apparent that other modifications can be made within the spirit and scope of this invention, and it is not intended to limit the invention to the exact details shown above except insofar as they are defined in the following claims.

The invention claimed is:

1. A polymer having a plurality of repeating units in the polymer molecules thereof having a formula in which Y is a polyvalent hydrocarbon radical having each of its valencies attached to a magnesium atom, and having each of said valencies of said polyvalent hydrocarbon radical extending from an aliphatic carbon atom therein which aliphatic carbon atom is in turn attached to at least one other aliphatic carbon atom.

2. A polymer having a plurality of repeating units in the polymer molecules thereof having the formula MgC H C H C H 3. A polymer having a plurality of repeating units in the polymer molecules thereof having the formula 4. A polymer having a plurality of repeating units in the polymer molecules thereof having the formula 5. A polymer having a plurality of repeating units the polymer molecules thereof having the formula 6. A polymer having a plurality of repeating units the polymer molecules thereof having the formula 2 4 io e 2 4 7. A polymer having a plurality of repeating units the polymer molecules thereof having the formula 8. A polymer having a plurality of repeating units the polymer molecules thereof having a formula 9. A polymer having a plurality of repeating units the polymer molecules thereof having a formula 10. A polymer having a plurality of repeating units the polymer molecules thereof having a formula 11. A process for the preparation of a polymer comprising the step of reacting at least one magnesium compound having the formula MgR wherein R is selected from the class consisting of hydrogen and hydrocarbon radicals having no more than 24 carbon atoms therein, with at least one hydrocarbon compound selected from the class consisting of (l) monoacetylenic hydrocarbons having no other unsaturated groups therein and (2) hydrocarbon compounds having a plurality of unsaturated groups therein selected from the class consisting of ethylenic and acetylenic groups, said reaction being conducted at a temperature below the decomposition temperature of said magnesium compound until an average of at least about 4 magnesium atoms are present in each polymer molecule.

12. A process of claim 11 in which said reaction is conducted at a temperature in the range of 50140 C.

13. A process of claim 12 in which said magnesium compound is magnesium hydride, and said reaction is conducted at least initially in the range of 50-80" C.

14. A process of claim 12 in which said magnesium compound is a magnesium dialkyl and at least part of the reaction is conducted at a temperature in the range of -140 C.

15. A process of claim 14 in which said magnesium dialkyl is magnesium dibutyl.

16. A process of claim 14 in which said magnesium dialkyl is magnesium diethyl.

17. A process of claim 12 in which said magnesium compound has one alkyl group per magnesium atom.

18. A process of claim 11 in which said hydrocarbon compound has a plurality of groups therein selected from the class consisting of vinyl, vinylidene and terminal acetylenic groups.

19. A process of claim 18 in which said hydrocarbon compound is divinyl benzene.

20. A process of claim 11 in which said magnesium compound is magnesium hydride and said hydrocarbon compound has a plurality of groups therein selected from the class consisting of vinyl, vinylidene and terminal acetylenic groups.

References Cited by the Examiner UNITED STATES PATENTS 2,931,793 4/ 1960 Melchore 260-93.5 2,980,661 4/1961 Twaddle et al. 260-935 3,018,203 l/1962 Guth 149-19 3,028,271 4/1962 Dixon et a1. l49l9 LEON D. ROSDOL, Primary Examiner.

CARL D. QUARFORTH, Examiner.

B. R. PADGETT, Assistant Examiner. 

1. A POLYMER HAVING A PLURALITY OF REPEATING UNITS IN THE POLYMER MOLECULES THEREOF HAVING A FORMULA 